Habitable zone 'Super Earth' candidate planet detected

A nearby star appears ​to be circled by six planets, including one "Super Earth" world that orbits at distances that could allow the existence of oceans, astronomers report.

Astronomers had earlier reported that three planets closely orbit the star, HD 40307, which is about 43 light years away (one light year is about 5.9 trillion miles). Now in the forthcoming Astronomy & Astrophysics journal report led by Mikko Tuomi of the United Kingdom's University of Hertfordshire, the team reports three more planets larger than Earth — but not as big as Jupiter — likely orbit the star.

One, dubbed HD 40307g, weighs at least seven times more than Earth and orbits the star on a 200-day "year" in the region amenable to liquid oceans on planets. (If planets orbit too close to their stars, they're likely too hot to support oceans.)

"The star HD 40307, is a perfectly quiet old dwarf star, so there is no reason why such a planet could not sustain an Earth-like climate," says study co-author Guillem Anglada-Escude of the University of Goettingen, in a statement.